The federal government has approved a COVID-19 vaccine that specifically targets two coronavirus variants of concern, including the original Omicron strain.
Health Minister Mark Butler said the government had accepted a recommendation from the Australian Technical Advisory Group on Immunisation (ATAGI) on the use of a new Moderna vaccine as a booster shot for people aged 18 years and older.
The move marks the first time a multi-strain COVID vaccine — otherwise known as a bivalent vaccine — has been approved for use in Australia.
The new shot is already being used in other countries, including Canada and the United Kingdom.
Unlike other approved vaccines, which only target the original Wuhan strain of the SARS-CoV-2 virus, the bivalent one also targets the original Omicron BA.1 strain.
"This is an important first step in showing how mRNA vaccines can be adapted to different dominant variants and subvariants," Mr Butler said in a statement.
The first doses of the bivalent vaccine have already arrived in the country and will now undergo batch testing by Australia's medical regulator, the Therapeutic Goods Administration (TGA).
They will be introduced into the rollout as existing stocks of Moderna's already-approved COVID-19 vaccine are exhausted.
How effective is it?
The vaccines already in use in Australia provide protection from severe disease against Omicron subvariant infections, but ATAGI found Moderna's bivalent shot provides a modest improvement in the body's immune response.
All jabs provide significant protection from severe disease against Omicron subvariant infections.
Infectious disease physician and microbiologist Paul Griffin, from the University of Queensland, said the approval of the bivalent vaccine did not "detract from how well our original vaccines have worked".
"The virus has continued to change and so we need to update our vaccines accordingly," he said.
Infectious diseases expert Robert Booy said lab data showed this bivalent vaccine was helpful in preventing infection from all Omicron variants, over and above what existing vaccines are expected to provide.
"However we don't know about efficacy because that requires doing a study of many thousands of people, so we have to rely on the immunogenicity, the antibody production," he said.
"And we know that neutralising antibodies with the vaccine are high and protective against the common Omicron strains BA.4 and BA.5."
"But we can see that the vaccine is effective [and] worth having."
Professor Booy also said the bivalent vaccine could be used as a fifth shot in the future.
"So if you've had four … you would have had the most recent one within the last few months, and that would protect you until at least Christmas," he said.
"So it might be something you do in March or April, at the same time you get your flu jab."
Dr Griffin said it could also help keep Australians safe for some time to come.
"The thought there is that it'll get better, broader cross-protection, maybe even against new emerging variants when they do arise," he said.
